1. Field of the Invention
The present invention relates to data storage apparatus for magnetically read and writing information on data storage media. More particularly, the invention concerns the interconnections of termination pads and leads in disk drive Integrated Lead Suspension (ILS) assemblies that mount micro-actuators with attached air bearing sliders.
2. Description of the Prior Art
By way of background, a read/write transducer of a magnetic disk drive storage device is typically mounted on an air bearing slider that is designed to fly closely above the surface of a spinning magnetic disk medium during drive operation. In older drive designs, the slider is mounted directly on a suspension assembly that is cantilevered from the arm of a pivotable actuator. More recently, micro-actuators have been proposed which facilitate fine positioning adjustments to help maintain the transducers above track centerlines.
A disk drive suspension assembly conventionally includes a load beam that attaches to the actuator arm and a flexure assembly that mounts to the load beam and carries the slider in a gimbaled arrangement. In an ILS assembly, the flexure assembly incorporates a laminated conductive lead system for interconnecting the transducer and the disk drive read/write electronics. If the suspension is to include a micro-actuator, there will also be leads to control micro-actuator positioning. Each of these leads must be properly connected at the slider end of the suspension assembly. For that purpose, two levels of electrical terminations are made. At the first level, there will be four terminations between the slider and the micro-actuator to electrically connect the read transducer (two connections required) and the write transducer (two connections required). At the second level, there will be eight terminations between the micro-actuator and the conductive leads of the ILS assembly. Four terminations are associated with the read and write sensors, and four terminations are associated with positioning the micro-actuator itself. In all, twelve terminations need to be made at the first and second levels.
The four slider-to-micro-actuator interconnections and the eight micro-actuator-to-ILS interconnections could possibly be made using a conventional wire bonding method. However, there are serious drawbacks in using this approach, to wit: a) a wire bonding process applies pad forces on the order of 100 grams, which is well beyond the 1-2 gram force that the fragile micro-actuator pads would be able to withstand; and b) the handling of eight fine wires to be attached to the micro-actuator would be extremely difficult in manufacturing.
Another possible slider/micro-actuator connectivity approach would be to use ultrasonic bonding of ILS bent leads, where the ends of the leads are bent into a plane that is generally parallel to the plane of a set of electrical terminal pads formed on the micro-actuator side edge. Again, there are serious drawbacks with this approach, to wit: a) the process of making the micro-actuator does not provide a method of forming pads on the side edge; and b) ultrasonic bonding also requires approximately 100 grams of force on the micro-actuator.
In light of the foregoing, an improved slider/micro-actuator connection approach is indicated. What is required is a new termination configuration and method in which a) hard wiring of the slider and micro-actuator is not required, b) wire bonding is avoided, and c) electrical terminals do not have to be placed on micro-actuator side edges.